Studies of Osteoclast Lineage in Health and Diseases

健康和疾病中破骨细胞谱系的研究

• 批准号: 10217391
• 负责人: Joseph A Lorenzo
• 金额: $ 21.48万
• 依托单位: UNIVERSITY OF CONNECTICUT SCH OF MED/DNT
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-06-23 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10217391
• 关键词: Adoptive Transfer; Age; Blood; Blood Circulation; Bone Diseases; Bone Marrow; Bone callus; CX3CR1 gene; Calvaria; Cells; Data; Development; Disease; Disease model; Drug Targeting; Engraftment; Femoral Fractures; Fracture; Gene Deletion; Goals; Health; Home; Homeostasis; Homing; Inflammation; Inflammatory; Kinetics; Label; Marrow; Modeling; Molecular; Monitor; Mus; Myelogenous; Osteitis; Osteoclasts; Osteolysis; Osteolytic; Parabiosis; Phenotype; Population; Process; Role; Signal Transduction; Site; Source; Spleen; TNF gene; Testing; Time; Vascular blood supply; bone; bone fracture repair; bone turnover; chemokine receptor; defined contribution; experimental study; in vivo; migration; osteoclast progenitor; progenitor; recruit; repaired; therapy design; therapy development; trafficking

Although, we know much about the molecular signals that regulate OC function, we know relatively little about the lineage and mechanisms that OC use to develop from progenitors. The goal of this application is to better define OC progenitor (OCP) maturation and trafficking and the mechanisms regulating this process in health and disease so that we can identify potential drug targets to develop superior therapies for bone diseases. The central hypotheses are: 1) During homeostasis marrow-resident cells are the principal OCP source, while during inflammation or fracture repair, circulating cells become a significant source of OCP. 2) The mechanisms regulating OCP migration, engraftment and maturation to OC in bone differ between healthy and disease states. To test these hypotheses, we propose the following aims: 1. Define the role that CX3CR1+ OCP have in OC development during homeostasis and identify mechanisms regulating their homing, engraftment and maturation to OC: 1A) Perform time course studies in CX3CR1-CreERT2-Ai14 mice at various ages to examine labeled OC formation kinetics. We will also monitor the kinetics of labeled OCP in the bone marrow, blood and spleen. 1B) The chemokine receptor CX3CR1 is expressed on OCP and has previously been implicated to influence OCP homing, engraftment and maturation. We will determine its role in OCP lineage development and trafficking in vivo under homeostatic conditions (when marrow-derived cells predominate as the OCP source) using CX3CR1-CreERT2-Ai14 mice to generate Cx3cr1 gene deletions. 2. Examine OCP homing from the circulation during bone inflammation and fracture repair. These studies will examine two disease models in which we previously demonstrated that circulating OCP are recruited to engraft in bone: TNFa-induced bone inflammation and a repairing fracture. 2A) Study a TNFa-induced inflammatory bone model (a WT parabiont has TNFα injected over its calvaria; the other parabiont is a CX3CR1-EGFP; TRAP-tdTomato mouse) and determine the rate that circulating labeled cells home to the inflammatory site, form OC and disappear. 2B) Study a parabiosis fracture model (a WT parabiont receives a femur fracture; the other parabiont is a CX3CR1-EGFP; TRAP-tdTomato mouse) and determine the rate that circulating labeled cells home to the repairing callus, form OC and disappear. 2C) Determine the phenotype and kinetics of circulating OCP that home, mature and engraft in bone with TNFa-induced inflammation or fracture repair by injecting selected populations of OCP from CX3CR1-EGFP; TRAP-tdTomato mice and monitoring the rates that labeled OC appear and disappear in bone. 2D) Determine the effect that deletion of Cx3cr1 has on the ability of circulating OCP to home, engraft and mature in bone with TNFa-induced inflammation or a fracture repair using parabiosis and adoptive transfer.

虽然，我们对调节OC功能的分子信号了解很多，但我们对 OC用于从祖细胞发展的谱系和机制。该应用的目的是更好 定义OC祖细胞（OCP）成熟和贩运以及在健康方面的机制 和疾病，以便我们可以确定潜在的药物靶标，以开发出骨病的优质疗法。这 中心假设是：1）在体内骨骨化过程中，骨髓居民细胞是主要的OCP来源， 在炎症或断裂修复期间，循环细胞成为OCP的重要来源。 2）调查OCP迁移，植入和成熟到OC的机制不同 在健康状态和疾病状态之间。为了检验这些假设，我们提出以下目的： 1。定义CX3CR1+ OCP在稳态期间OC发育中的作用并确定 将其归宿，植入和成熟的机制转化为OC： 1A）在CX3CR1-CREERT2-AI14小鼠的各个年龄进行时间课程研究以检查标记的OC 编队动力学。我们还将监测骨髓，血液和索伦中标记的OCP的动力学。 1b）趋化因子受体CX3CR1在OCP上表达，以前牵涉到影响 OCP归巢，植入和成熟。我们将确定其在OCP谱系发展中的作用 在体内稳态条件下（骨髓衍生的细胞占OCP来源）的体内运输） 使用CX3CR1-CREERT2-AI14小鼠生成CX3CR1基因缺失。 2。检查骨骼注射和断裂修复过程中循环中的OCP归巢。 这些研究将研究两个疾病模型，我们以前证明了循环OCP是 招募以植入骨头：TNFA诱导的骨注射和修复骨折。 2A）研究TNFA诱导的炎症骨模型（WT副抗合体在其钙质上注射了TNFα； 其他抛物线是CX3CR1-EGFP；陷阱-TDTOMATO鼠标）并确定循环标记的速率 细胞回家炎症部位，形成OC并消失。 2b）研究抛物线抗体骨折模型（WT parabiont接受了股骨骨折；另一个副骨是一个 CX3CR1-EGFP;陷阱-TDTOMATO小鼠），并确定循环标记的细胞回家的速率 修复愈伤组织，形成OC并消失。 2C）确定循环OCP的表型和动力学，该家庭，成熟并植入骨骼中的表型和动力学 通过从CX3CR1-EGFP注入选定的OCP群体，TNFA诱导的注射或断裂修复； 诱捕-tdttomato小鼠并监测标记OC外观并消失在骨骼中的速率。 2d）确定CX3CR1缺失对循环OCP到家，植入和 使用抛物线和适应性转移，具有TNFA诱导的感染或骨折修复的骨骼成熟。